Add preview checkbox for LivePicker

Enable preview checkbox to hide bottom panel, otherwise to show it.
Default behavior will show bottom panel with preview unchecked.

Bug: 130383883
Test: Manual Test

Change-Id: Ida5a5fa7ece501aefd906b70b6990eb89fe14c74

7 files changed, 140 insertions, 48 deletions

diff --git a/res/layout/live_wallpaper_preview.xml b/res/layout/live_wallpaper_preview.xml
index 0c35b68..b6bbd7c 100644
--- a/res/layout/live_wallpaper_preview.xml
+++ b/res/layout/live_wallpaper_preview.xml
@@ -46,29 +46,37 @@
         android:layout_height="match_parent"
         android:fitsSystemWindows="true">
 
-        <LinearLayout
-            android:id="@+id/bottom_pane"
+        <androidx.coordinatorlayout.widget.CoordinatorLayout
+            android:id="@+id/coordinator_layout"
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
             android:layout_gravity="bottom"
-            android:background="@color/translucent_black"
             android:orientation="vertical">
 
-            <com.google.android.material.tabs.TabLayout
-                android:id="@+id/tablayout"
+            <LinearLayout
+                android:id="@+id/bottom_pane"
                 android:layout_width="match_parent"
                 android:layout_height="wrap_content"
-                style="@style/TabLayoutStyle"
-                android:visibility="gone" />
+                android:background="@color/translucent_black"
+                android:orientation="vertical"
+                app:behavior_peekHeight="@dimen/preview_attribution_pane_collapsed_height"
+                app:layout_behavior="com.google.android.material.bottomsheet.BottomSheetBehavior">
 
-            <com.android.wallpaper.livepicker.widget.ConstraintViewPager
-                android:id="@+id/viewpager"
-                android:layout_width="match_parent"
-                android:layout_height="wrap_content">
+                <com.google.android.material.tabs.TabLayout
+                    android:id="@+id/tablayout"
+                    android:layout_width="match_parent"
+                    android:layout_height="wrap_content"
+                    style="@style/TabLayoutStyle"
+                    android:visibility="gone"/>
+
+                <com.android.wallpaper.livepicker.widget.ConstraintViewPager
+                    android:id="@+id/viewpager"
+                    android:layout_width="match_parent"
+                    android:layout_height="wrap_content"/>
 
-            </com.android.wallpaper.livepicker.widget.ConstraintViewPager>
+            </LinearLayout>
 
-        </LinearLayout>
+        </androidx.coordinatorlayout.widget.CoordinatorLayout>
 
         <android.widget.Toolbar
             android:id="@+id/toolbar"
diff --git a/res/layout/preview_action.xml b/res/layout/preview_action.xml
new file mode 100644
index 0000000..89a3c9e
--- /dev/null
+++ b/res/layout/preview_action.xml
@@ -0,0 +1,24 @@
+<!-- Copyright (C) 2019 The Android Open Source Project
+
+     Licensed under the Apache License, Version 2.0 (the "License");
+     you may not use this file except in compliance with the License.
+     You may obtain a copy of the License at
+
+          http://www.apache.org/licenses/LICENSE-2.0
+
+     Unless required by applicable law or agreed to in writing, software
+     distributed under the License is distributed on an "AS IS" BASIS,
+     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+     See the License for the specific language governing permissions and
+     limitations under the License.
+-->
+
+<CheckBox
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    style="?android:attr/checkboxStyle"
+    android:layout_width="wrap_content"
+    android:layout_height="match_parent"
+    android:text="@string/preview"
+    android:textAllCaps="false"
+    android:textAppearance="?android:attr/actionMenuTextAppearance"
+    android:background="?android:attr/selectableItemBackgroundBorderless"/>
diff --git a/res/layout/set_wallpaper_action.xml b/res/layout/set_wallpaper_action.xml
deleted file mode 100644
index 02f4fcd..0000000
--- a/res/layout/set_wallpaper_action.xml
+++ /dev/null
@@ -1,24 +0,0 @@
-<!--
-  ~ Copyright (C) 2016 The Android Open Source Project
-  ~
-  ~ Licensed under the Apache License, Version 2.0 (the "License");
-  ~ you may not use this file except in compliance with the License.
-  ~ You may obtain a copy of the License at
-  ~
-  ~      http://www.apache.org/licenses/LICENSE-2.0
-  ~
-  ~ Unless required by applicable law or agreed to in writing, software
-  ~ distributed under the License is distributed on an "AS IS" BASIS,
-  ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-  ~ See the License for the specific language governing permissions and
-  ~ limitations under the License
-  -->
-
-<Button
-    xmlns:android="http://schemas.android.com/apk/res/android"
-    style="?android:attr/actionButtonStyle"
-    android:layout_width="wrap_content"
-    android:layout_height="match_parent"
-    android:text="@string/set_live_wallpaper"
-    android:textAppearance="?android:attr/actionMenuTextAppearance"
-    android:background="?android:attr/selectableItemBackgroundBorderless"/>
\ No newline at end of file
diff --git a/res/menu/menu_preview.xml b/res/menu/menu_preview.xml
index c8d450a..183ffd4 100644
--- a/res/menu/menu_preview.xml
+++ b/res/menu/menu_preview.xml
@@ -16,6 +16,11 @@
 -->
 <menu xmlns:android="http://schemas.android.com/apk/res/android" >
 
+    <item android:id="@+id/preview"
+          android:checkable="true"
+          android:showAsAction="ifRoom"
+          android:actionLayout="@layout/preview_action"/>
+
     <item
         android:id="@+id/configure"
         android:icon="@drawable/ic_settings"
diff --git a/res/values/dimensions.xml b/res/values/dimensions.xml
index 85ce7db..a1ccd3f 100644
--- a/res/values/dimensions.xml
+++ b/res/values/dimensions.xml
@@ -33,6 +33,7 @@
     <dimen name="preview_gradient_background_height">256dp</dimen>
 
     <!-- Dimensions for the preview attribution pane. -->
+    <dimen name="preview_attribution_pane_collapsed_height">0dp</dimen>
     <dimen name="preview_attribution_pane_horizontal_padding">24dp</dimen>
     <dimen name="preview_attribution_pane_extra_spacer_height">16dp</dimen>
     <dimen name="preview_attribution_pane_inner_spacer_height">14dp</dimen>
diff --git a/res/values/strings.xml b/res/values/strings.xml
index 824c23b..4ade992 100644
--- a/res/values/strings.xml
+++ b/res/values/strings.xml
@@ -33,6 +33,8 @@
     <string name="configure_wallpaper">Settings…</string>
     <!-- List item for deleting the current wallpaper -->
     <string name="delete_live_wallpaper">Delete</string>
+    <!-- List item for showing the current wallpaper by hiding bottom panel. -->
+    <string name="preview">Preview</string>
     <!-- Button label on Wallpaper Gallery screen; user selects this button to set a specific wallpaper -->
     <string name="wallpaper_instructions">Set wallpaper</string>
     <!-- Warning message, no live wallpapers available. -->
@@ -61,4 +63,12 @@
 
     <!-- Confirmation dialog. Shown after user selects to delete one wallpaper. [CHAR LIMIT=NONE]  -->
     <string name="delete_wallpaper_confirmation">Delete this wallpaper from your phone?</string>
+
+    <!-- Content description for a checkbox letting the user collapse a visual panel showing info
+         about the wallpaper being previewed. [CHAR LIMIT=none] -->
+    <string name="collapse_attribution_panel">Collapse wallpaper info panel</string>
+
+    <!-- Content description for a checkbox letting the user expand a visual panel showing info
+         about the wallpaper being previewed. [CHAR LIMIT=none] -->
+    <string name="expand_attribution_panel">Expand wallpaper info panel</string>
 </resources>
diff --git a/src/com/android/wallpaper/livepicker/LiveWallpaperPreview.java b/src/com/android/wallpaper/livepicker/LiveWallpaperPreview.java
index 7cfdb4d..65e0e6c 100644
--- a/src/com/android/wallpaper/livepicker/LiveWallpaperPreview.java
+++ b/src/com/android/wallpaper/livepicker/LiveWallpaperPreview.java
@@ -43,7 +43,6 @@ import android.service.wallpaper.IWallpaperEngine;
 import android.service.wallpaper.IWallpaperService;
 import android.service.wallpaper.WallpaperService;
 import android.service.wallpaper.WallpaperSettingsActivity;
-import com.google.android.material.tabs.TabLayout;
 import android.text.TextUtils;
 import android.util.Log;
 import android.util.Pair;
@@ -58,6 +57,7 @@ import android.view.WindowManager.LayoutParams;
 import android.view.animation.AnimationUtils;
 import android.widget.ArrayAdapter;
 import android.widget.Button;
+import android.widget.CheckBox;
 import android.widget.TextView;
 import android.widget.Toolbar;
 
@@ -71,6 +71,10 @@ import androidx.slice.widget.SliceView;
 import androidx.viewpager.widget.PagerAdapter;
 import androidx.viewpager.widget.ViewPager;
 
+import com.google.android.material.bottomsheet.BottomSheetBehavior;
+import com.google.android.material.bottomsheet.BottomSheetBehavior.BottomSheetCallback;
+import com.google.android.material.tabs.TabLayout;
+
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
@@ -90,6 +94,11 @@ public class LiveWallpaperPreview extends Activity {
     private Intent mDeleteIntent;
 
     private View mLoading;
+    private View mViewBottomPane;
+    private BottomSheetBehavior mBottomSheetBehavior;
+    private ViewPager mViewPager;
+    private TabLayout mTabLayout;
+    private CheckBox mPreview;
 
     protected final List<Pair<String, View>> mPages = new ArrayList<>();
     private SliceView mSliceViewSettings;
@@ -282,9 +291,12 @@ public class LiveWallpaperPreview extends Activity {
     }
 
     private void populateBottomPane() {
-        final View viewBottomPane = findViewById(R.id.bottom_pane);
-        final ViewPager viewPager = findViewById(R.id.viewpager);
-        final TabLayout tabLayout = findViewById(R.id.tablayout);
+        mViewBottomPane = findViewById(R.id.bottom_pane);
+        mViewPager = findViewById(R.id.viewpager);
+        mTabLayout = findViewById(R.id.tablayout);
+
+        mBottomSheetBehavior = BottomSheetBehavior.from(mViewBottomPane);
+        mBottomSheetBehavior.setState(BottomSheetBehavior.STATE_EXPANDED);
 
         // Create PagerAdapter
         final PagerAdapter pagerAdapter = new PagerAdapter() {
@@ -325,24 +337,24 @@ public class LiveWallpaperPreview extends Activity {
         };
 
         // Add OnPageChangeListener to re-measure ViewPager's height
-        viewPager.addOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
+        mViewPager.addOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
             @Override
             public void onPageSelected(int position) {
-                viewPager.requestLayout();
+                mViewPager.requestLayout();
             }
         });
 
         // Set PagerAdapter
-        viewPager.setAdapter(pagerAdapter);
+        mViewPager.setAdapter(pagerAdapter);
 
         // Make TabLayout visible if there are more than one page
         if (mPages.size() > 1) {
-            tabLayout.setVisibility(View.VISIBLE);
-            tabLayout.setupWithViewPager(viewPager);
+            mTabLayout.setVisibility(View.VISIBLE);
+            mTabLayout.setupWithViewPager(mViewPager);
         }
 
         // Initializes a rounded rectangle outline and clips the upper corners to be rounded.
-        viewBottomPane.setOutlineProvider(new ViewOutlineProvider() {
+        mViewBottomPane.setOutlineProvider(new ViewOutlineProvider() {
             private final int radius = getResources().getDimensionPixelSize(
                     R.dimen.preview_viewpager_round_radius);
 
@@ -352,17 +364,73 @@ public class LiveWallpaperPreview extends Activity {
                         view.getHeight() + radius, radius);
             }
         });
-        viewBottomPane.setClipToOutline(true);
+        mViewBottomPane.setClipToOutline(true);
     }
 
     @Override
     public boolean onCreateOptionsMenu(Menu menu) {
         getMenuInflater().inflate(R.menu.menu_preview, menu);
+        setupPreviewMenu(menu);
         menu.findItem(R.id.configure).setVisible(mSettingsIntent != null);
         menu.findItem(R.id.delete_wallpaper).setVisible(mDeleteIntent != null);
         return super.onCreateOptionsMenu(menu);
     }
 
+    private void setupPreviewMenu(Menu menu) {
+        mPreview = (CheckBox) menu.findItem(R.id.preview).getActionView();
+        mPreview.setOnClickListener(this::setPreviewBehavior);
+
+        BottomSheetCallback callback = new BottomSheetCallback() {
+            @Override
+            public void onStateChanged(View bottomSheet, int newState) {
+                switch (newState) {
+                    case BottomSheetBehavior.STATE_COLLAPSED:
+                        setPreviewChecked(true /* checked */);
+                        break;
+                    case BottomSheetBehavior.STATE_EXPANDED:
+                        setPreviewChecked(false /* checked */);
+                        break;
+                }
+            }
+
+            @Override
+            public void onSlide(View bottomSheet, float slideOffset) {
+                mTabLayout.setAlpha(slideOffset);
+                mViewPager.setAlpha(slideOffset);
+            }
+        };
+        mBottomSheetBehavior.setBottomSheetCallback(callback);
+
+        int state = mBottomSheetBehavior.getState();
+        callback.onStateChanged(mViewBottomPane, state);
+        switch (state) {
+            case BottomSheetBehavior.STATE_COLLAPSED:
+                callback.onSlide(mViewBottomPane, 0f);
+                break;
+            case BottomSheetBehavior.STATE_EXPANDED:
+                callback.onSlide(mViewBottomPane, 1f);
+                break;
+        }
+    }
+
+    private void setPreviewChecked(boolean checked) {
+        if (mPreview != null) {
+            mPreview.setChecked(checked);
+            int resId = checked ? R.string.expand_attribution_panel
+                    : R.string.collapse_attribution_panel;
+            mPreview.setContentDescription(getResources().getString(resId));
+        }
+    }
+
+    private void setPreviewBehavior(final View v) {
+        CheckBox checkbox = (CheckBox) v;
+        if (checkbox.isChecked()) {
+            mBottomSheetBehavior.setState(BottomSheetBehavior.STATE_COLLAPSED);
+        } else {
+            mBottomSheetBehavior.setState(BottomSheetBehavior.STATE_EXPANDED);
+        }
+    }
+
     public void setLiveWallpaper(final View v) {
         if (mWallpaperManager.getWallpaperInfo() != null
                 && mWallpaperManager.getWallpaperId(WallpaperManager.FLAG_LOCK) < 0) {